I've been waiting to get some facts before contributing to this thread. Finally tracked someone down withing Department of Health who knows what they're talking about.
The term "physio-" is now regulated - you can no longer use it unless you have the proper qualification that would previously have qualified someone for "state registered" status.
BUT there is not yet a continuing professional development regime in place for physiotherapists and similar professions. This means that someone could have qualified twenty years ago and be completely out of date as far as current techniques are concerned - may in fact not have practised for a long term.
Apparently nearly all good physios are attached to the major teaching hospitals, so expect to go to one if you want the best.
Another piece of advice is don't self refer - go through your GP, who should know the good ones, even if you want to pay to go privately.